@types/chai conflict with @vitest/expect/dist/chai.d.cts

[antoniosZ]

Describe the bug

since v1.0.0-beta.1
5996c8c0

I get the following:

../../node_modules/@types/chai/index.d.ts:1:1 - error TS6200: Definitions of the following identifiers conflict with those in another file: Message, ObjectProperty, ChaiPlugin, AssertionArgs, Operator, OperatorComparable, AssertionError, chai

1 declare namespace Chai {
  ~~~~~~~

  ../../node_modules/vitest/node_modules/@vitest/expect/dist/chai.d.cts:16:1
    16 declare namespace Chai {
       ~~~~~~~
    Conflicts are in this file.

../../node_modules/vitest/node_modules/@vitest/expect/dist/chai.d.cts:16:1 - error TS6200: Definitions of the following identifiers conflict with those in another file: Message, ObjectProperty, ChaiPlugin, AssertionArgs, Operator, OperatorComparable, AssertionError, chai

16 declare namespace Chai {
   ~~~~~~~

  ../../node_modules/@types/chai/index.d.ts:1:1
    1 declare namespace Chai {
      ~~~~~~~
    Conflicts are in this file.


Found 2 errors in 2 files.

In case it matters, this is an NPM workspace project.
If I delete the file node_modules/vitest/node_modules/@vitest/expect/dist/chai.d.cts everything compiles successfully like before the upgrade to v1.0.0-beta.1.

Reproduction

install and try to compile without skipLibCheck: true in tsconfig

System Info

System:
    OS: macOS 13.6.1
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.9.0 - ~/.nvm/versions/node/v20.9.0/bin/node
    npm: 10.2.1 - ~/my-project/node_modules/.bin/npm
  npmPackages:
    @vitest/coverage-v8: ^1.0.1 => 1.0.1 
    vite: ^5.0.6 => 5.0.6

Used Package Manager

npm

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• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
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• The provided reproduction is a minimal reproducible example of the bug.

[sheremet-va]

Why do you have @types/chai installed?

[antoniosZ]

@sheremet-va they are indirect/nested deps

npm list @types/chai
@my-project
  ├─┬ @storybook/[email protected]
  │ └── @types/[email protected]
  └─┬ [email protected]
    ├─┬ @types/[email protected]
    │ └── @types/[email protected] deduped
    └── @types/[email protected] deduped

[sheremet-va]

I wonder if this should be fixed on storybook side - they are using chai to use @vitest/expect (form what I gathered here: storybookjs/storybook#17326). It's no longer needed because we bundle it together with @vitest/expect package because of #2118

We can also try to improve @types/chai package but I have no idea how to reach maintainers there.

[antoniosZ]

@sheremet-va I removed the @storybook/test package and I still get the same conflict with the following

$npm list @types/chai
@testing-library/[email protected]
    └─┬ [email protected]
      ├─┬ @types/[email protected]
      │ └── @types/[email protected] deduped
      └── @types/[email protected]

[antoniosZ]

https://github.com/testing-library/jest-dom/blob/main/package.json#L104

seems like to resolve this, everyone else has to remove their @types/chai dependency or vitest has to remove their bundled typings of chai...

[sheremet-va]

https://github.com/testing-library/jest-dom/blob/main/package.json#L104

seems like to resolve this, everyone else has to remove their @types/chai dependency or vitest has to remove their bundled typings of chai...

This is a dev dependency, it's not installed. jest-dom has a peer dependency of Vitest which should just reuse existing one. Try deleting a lockfile and installing everything again.

[antoniosZ]

@sheremet-va I just created a minimal reproduction...
https://stackblitz.com/edit/vitest-dev-vitest-nowys5?file=package.json
if you run in the terminal tsc you will see the conflict...

@storybook/test for sure creates the conflict

[antoniosZ]

the way I see this, any other package that has @types/chai as a dependency, will cause a conflict with vitest, just because vitest embeds the chai typings. But I could be wrong in my understanding here.

[antoniosZ]

one more reproduction, this time with the nightwatch package, to hopefully demonstrate, that the issue IMO is not isolated to @storybook/test...

https://stackblitz.com/edit/vitest-dev-vitest-qwc3pw?file=package.json

[majo44]

Hi, we have also this issue.

We have huge monorepo (~400 packages/rush/pnpm), we are on the mocha/chai/sinon, and we made a try to migrate package by package to vitests. In general tests runs well, but compilation (type checking) on packages where we are using the vitest fails with:

../../../../common/temp/node_modules/.pnpm/@[email protected]/node_modules/@types/chai/index.d.ts:1:1 - error TS6200: Definitions of the following identifiers conflict with those in another file: Message, ObjectProperty, ChaiPlugin, AssertionArgs, Operator, OperatorComparable, AssertionError, chai

1 declare namespace Chai {
  ~~~~~~~

  ../../../../common/temp/node_modules/.pnpm/@[email protected]/node_modules/@vitest/expect/dist/chai.d.cts:16:1
    16 declare namespace Chai {
       ~~~~~~~
    Conflicts are in this file.

../../../../common/temp/node_modules/.pnpm/@[email protected]/node_modules/@vitest/expect/dist/chai.d.cts:16:1 - error TS6200: Definitions of the following identifiers conflict with those in another file: Message, ObjectProperty, ChaiPlugin, AssertionArgs, Operator, OperatorComparable, AssertionError, chai

16 declare namespace Chai {
   ~~~~~~~

  ../../../../common/temp/node_modules/.pnpm/@[email protected]/node_modules/@types/chai/index.d.ts:1:1
    1 declare namespace Chai {
      ~~~~~~~
    Conflicts are in this file.


Found 2 errors in 2 files.

Errors  Files
     1  ../../../../common/temp/node_modules/.pnpm/@[email protected]/node_modules/@types/chai/index.d.ts:1
     1  ../../../../common/temp/node_modules/.pnpm/@[email protected]/node_modules/@vitest/expect/dist/chai.d.cts:16

The package itself is not depends on the @types/chai, but probably somewhere deep in the tree we (or 3partpy dep or dev dep) has such dependency/devDependecy, so it is installed in the tree, but .... funny is that the vitests is causing of loading of @types/chai, during the compilation:

tsc --explainFiles says:

../../../../common/temp/node_modules/.pnpm/@[email protected]/node_modules/@types/chai/index.d.ts
  Imported via 'chai' from file '../../../../common/temp/node_modules/.pnpm/[email protected]_@[email protected]/node_modules/vitest/dist/reporters-O4LBziQ_.d.ts' with packageId '@types/chai/[email protected]'
  Imported via 'chai' from file '../../../../common/temp/node_modules/.pnpm/[email protected]_@[email protected]/node_modules/vitest/dist/index.d.ts' with packageId '@types/chai/[email protected]'

In vitest 0.34 there was no such problem as vitest used the @types/chai instead of re-declare it internally.

[qraynaud]

Did someone find a workaround for this? This is very cumbersome…

[qraynaud]

Okay, I just found that adding skipLibCheck: true to the tsconfig.json/compilerOptions is doing the trick.

[kasperpeulen]

Trying to fix this in the next patch release of @storybook/test.

[Abdillah]

This seems to be Vitest issue.

Chai is obviously should not be included along with user facing vitest type. If Vitest has resemblance with Chai, it should be hidden.

[danielrentz]

I see a similar problem after upgrading vitest from 2.0.4 to 2.0.5

Without having @types/chai installed, I see

node_modules/vitest/dist/chunks/reporters.C_zwCd4j.d.ts:17:23 - error TS7016: Could not find a declaration file for module 'chai'. '.../node_modules/chai/chai.js' implicitly has an 'any' type.
  Try `npm i --save-dev @types/chai` if it exists or add a new declaration (.d.ts) file containing `declare module 'chai';`

17 import * as chai from 'chai';
                         ~~~~~~
Found 1 error in node_modules/vitest/dist/chunks/reporters.C_zwCd4j.d.ts:17

After installing @types/chai as suggested, I see

node_modules/@types/chai/index.d.ts:1:1 - error TS6200: Definitions of the following identifiers conflict with those in another file: Message, ObjectProperty, ChaiPlugin, AssertionArgs, Operator, OperatorComparable, AssertionError, chai

1 declare namespace Chai {
  ~~~~~~~

  node_modules/@vitest/expect/dist/chai.d.cts:16:1
    16 declare namespace Chai {
       ~~~~~~~
    Conflicts are in this file.

node_modules/@vitest/expect/dist/chai.d.cts:16:1 - error TS6200: Definitions of the following identifiers conflict with those in another file: Message, ObjectProperty, ChaiPlugin, AssertionArgs, Operator, OperatorComparable, AssertionError, chai

16 declare namespace Chai {
   ~~~~~~~

  node_modules/@types/chai/index.d.ts:1:1
    1 declare namespace Chai {
      ~~~~~~~
    Conflicts are in this file.

Found 2 errors in 2 files.

Errors  Files
     1  node_modules/@types/chai/index.d.ts:1
     1  node_modules/@vitest/expect/dist/chai.d.cts:16

[Jym77]

Running into this too.
My use case is that I try to build integrations of my library with various test frameworks (so that end-user can more easily use it).

So, I have a monorepo alfa-integrations where the existing package alfa-chai is importing Chai and its types. I'm trying to create an alfa-vitest package, importing Vitest. But every dependency in a monorepo is hosted in the root node_modules and somehow just having vitest and @types/chai there causes this problem.

[tassoevan]

Seeing it happen in a codebase with @storybook/test (depends on @vitest/expect) and @types/chai. It broke all assert.isDefined() calls as the function went from being an assertion function to a void-returning function.